Joseph trent



- @uit-rh tant strnt @Hita Letters Patent No. 76,557, dated April 7, 1868.

IMPROVEMENT IN VOLUTE SPRINGS.

tlge tlpmle referat tu "in tipa hutten; iiteut :mt mating nrt uf tigt time.

TO ALL WHOM IT MAY CONGERN: f

Beit known that I, JOSEPH TEENT', of Millerton, in the county of Dutchess, and State of New York, have invented a new and useful Improvement in Volute Springsj'and I do herehydeclare that the following is a full, clear, and exact description of the same, reference being had to the accompanying' drawings, forming part of this specication,`in which-,-

Figure l is a side elevation'oi the complete spring.

Figure 2 is a longitudinal vertical section thereof, taken on the plane of the line x x, iig. I;

Figure 3 is a plan 'View of a strip of nietalbef'orethc same is rolled up to constitute the spring shown in fig. 1.

This invention consists in anew article ofinanutacture, namely, aquadruple' volute spring, .formed by rolling up a plate or strip of metal having four legs or arms, two at'each end, the said arms being separated by somewhat lVlshaped slots, thereby-producing a quadruple volute spring, possessing great sustaining power', with arequisite amount of ileXibi-lity, A i

It also consists in an improvedmode ormanner' of constructing the .said plate of which the spring is formed, to wit, by punching out or otherwise removing from said plate a somewhatvV-shaped piece or pieces, the practice heretoforevh-aving'-heentocut a slitin the metal, andv forcing apart the separated pieces to Form the legs or arms, as described in av patent granted to one Freeland and one Ward on the 7th March, 1865, one ofA the great disadvantages to this last-named practice being that the legs cr arms are liable to get back to their normal condition orfset," thus'destro 'infr' the effect-ive nalities of the s rin whereas, with m invention, the lefrs or 5 a l P g Y a arms are naturally at a certain Adistance apart, and when pressed together,- as when the Spring is sustaining a weight, they immediately resume their normal condition when the pressure is relieved, thereby cbviating any material set" in the spring.

,In the manufacture of the spring, a number of plates maybe struck in the required shape by a stampingmachine. 1 Y

In g. lof the drawings I have shown a platcofv a construction which I find ity preferable to use. A designates the solid central portion ofthe plate or strip, and B B the legs or arms onthe one side, and B"B the legs or arms on the other side. `In forming these legs, a somewhat V-shaped piece is stamped out or otherwise removed from each end of the plate-or strip, whereby great advantage is obtained, as' above mentioned.

At the apex of each slot I iind it preferable to malte a puncture or hole, a, which has the effect, -when the plate or strip is rolled up to form the spring, to prevent the two arms of each set crowding past or overlapping' each othera contingency likely tooccur were'the slot to terminate at a sharp angle. f The advantages arising from forming a puncture or hole at the terminationof each slot will be easily perceived bycoinpressing the spring to itsminimum capacity. y I L I also find it preferable to form the arms B B and BB with parallel outer edgesb, commencing at their ends, and extending'up a suiiicient distance' to insure, when the plate-or strip is rolled upto form the spring, an even base at both ends for the spring to rest upon; and at the termination of thelparallel edges the outer edges of the plate are curvedconcavely, the greatest depth-oi` the` curve being at about the centre of the solid portion A, This curving of the plate gives the spring, it 'is believed, greater elasticity or fiexi'bility. A

l'.lhe plate or `strip, whether it be simply a plateor strip having a'V-shaped piece cut out from each end, or whether, inaddition to this, having the punetures-b, parallel bases, and .curved edges, may he rolled up around a mandrel, or'in any other suitable manner; and whe'nso made it'possesses many advantages over any spring of the same character now .knownf It is in effect equal to four ordinary volute springs combined in one and oper ating jointlyfthus giving the springgreat strength, and yet lsuilicient elasticity. Pressure upon it, while producing a verticalmotion, tends also tomove the outer coils' laterally in one direction,land the innercoils in just an opposite direction, so that no liability ofthe spring unwinding or uncoiling need be apprehended. Ihe compression ofthe spring increases its resistance; that is to say, alittle weight will operate the spring at first, but afterwards, the'heavier the weight, the greater the resistance, until the power of the spring is exhausted. The'spring has also a lateraltmotion in all directions.

I am aware that a patent was issued to John Freeland and Daniel Ward, on the 7th of-Mareh, 1865, for an" improvement in volut'e springs, wherein it'was specified that .a plate of metal, cut or divided longitudinally early its whole length, with the ont portion spread apart; was rolled up to form the spring; I therefore wish ydistinctly understood that I disclaim everything which is shown, described, and claimed in the said patent sthe inventioof said Freeland and Ward; but f What I claim as my invention, and desire to secure by Letters Patent, is y l 1. As n. new article of mamifactmre,` the quadruple volute spring, constructed in the manner herein'set forth. 2. The improvedmethod herein described ofvmanuf'acturng double orq'uadruple volute springs.

' JOSEPH TRENT.

Witnesses:

Gno. E. WooDwARn, E. Cms. HUssEY. 

